The sequence for shutting down a main transformer is as follows: when de-energizing, the load side should be shut down first, followed by the power supply side. For energizing operations, the reverse order applies: the power supply side is energized first, then the load side. This is because: Energizing from the power supply side to the load side makes it easier to identify the fault range and take prompt judgment and handling measures in case of a fault, preventing the fault from spreading or e

1 OverviewCases of transformer oil contaminated by microorganisms have been reported both domestically and internationally. Individual transformer manufacturers, user units, and research institutions have conducted specialized studies, but all focused on power transformers. This paper targets specialty transformers for specific applications (e.g., rectifier transformers for graphitization furnaces, submerged arc furnace transformers), exploring the process of microbial contamination of their tra

Verification of Insulation IntegrityWhen a new or overhauled transformer is energized under open-circuit (no-load) conditions, switching surges—caused by operations such as opening or closing the no-load transformer circuit—can generate overvoltages. These reach 4.0–4.5 times the phase voltage if the neutral point is isolated or earthed through a Petersen coil, and up to 3.0 times the phase voltage when the neutral is solidly grounded. The full-voltage, no-load impa

1. Functions of Transformer BushingsThe core function of transformer bushings is to lead the coil leads out to the external environment. They serve both as insulating components between the leads and the oil tank and as fixing devices for the leads.During the operation of a transformer, bushings continuously carry load currents and, in the event of an external short circuit, withstand short-circuit currents. Therefore, transformer bushings must meet the following requirements: Possess specified

1.Environmental Requirements for Transformer Core-Lifting Inspection1.1 General Environmental ConditionsCore - lifting operations are preferably carried out indoors. For large transformers that have to be operated outdoors due to specific conditions, sufficient measures must be taken to prevent moisture and dust contamination.Core - lifting should not be conducted during rainy or snowy weather or when the relative humidity exceeds 75%.The ambient air temperature during core - lifting should not

1. Brief Introduction to the Photovoltaic Power Generation ProcessThe operation process of photovoltaic power generation is as follows: First, individual solar panels are connected in series to form photovoltaic modules, and the modules are arranged in parallel through combiner boxes to form a photovoltaic array. Solar energy is converted into direct current (DC) by the photovoltaic array, and then converted into three-phase alternating current (AC) through a three-phase inverter (DC - AC). Subs